Welcome to Maseches Pe'ah. The tractate deals primarily with the gifts to the poor - those agricultural gifts that are given to a poor person. The first gift we will discuss is the mitzvah of pe'ah: the corner of the field that is left for the poor to gather. The first mishnah of chapter 1 deals with mitzvos that have no shiur, that is, no fixed measure, and the first of them is pe'ah.
"Eilu devarim she'ein lahem shiur":
These are the things that have no fixed measure. This is, of course, the mishnah that is recited every morning after the birchos haTorah.
"HaPe'ah" - it has no specific measure in the Torah, and even the smallest amount suffices. Although the Torah did not set a measure, the Sages did set an amount, as we will see later on. The same is true of several of the other mitzvos listed here, which may well have a rabbinic measure; our mishnah is referring to the fact that they have no measure from the Torah.
"VehaBikkurim" - the first fruits that are brought; they too have no measure.
"VehaRe'ayon" - the mitzvah of appearing. Three times a year, on the three festivals, one goes up to the Beis HaMikdash, as it says that all the males shall appear, and one may not come empty handed. There are two mitzvos here: to appear in the Beis HaMikdash in the courtyard, and also to bring an offering - the olas re'iyah that is bound up with the mitzvah of appearing, as well as the shalmei chagigah. There is no measure from the Torah for the number of times a person appears, and even a single moment in the Beis HaMikdash is enough; and likewise there is no measure for the amount of olas re'iyah and shalmei chagigah that a person may bring.
"U'gemilus chasadim" - it takes two forms: kindness done with a person's money, and kindness done with his body. Although the Sages instituted that with kindness done through money one should not give more than a fifth of the principal in his possession, from the Torah there is no measure for this.
"V'talmud Torah" - there is no measure for the study of Torah. True, one can fulfill the obligation at a minimum by reciting Shema morning and evening, but there is no limit to how much a person can learn.
"Eilu devarim she'adam ochel peiroseihem ba'olam hazeh, vehakeren kayemes lo la'olam haba":
The mishnah now moves to a different idea: these are the mitzvos whose fruits, the added benefit of the mitzvah, a person consumes in this world, while the principal is preserved to his credit for the World to Come. The list recited after the birchos haTorah is longer and comes from a beraisa; here we have the short list of the mishnah:
"Kibbud av va'em" - honoring one's parents.
"U'gemilus chasadim" - the mitzvah of doing kindness, with all the mitzvos included under that umbrella.
"Vehava'as shalom bein adam lachaveiro" - making peace between one person and his fellow.
"V'talmud Torah k'neged kulam" - the study of Torah is equal to all of them together.
In summary: in this mishnah we learned two lists: the first - things that have no measure from the Torah: pe'ah, bikkurim, re'ayon, gemilus chasadim and talmud Torah; and the second - things whose fruits a person consumes in this world while the principal remains for him in the World to Come: honoring one's father and mother, gemilus chasadim, bringing peace between a person and his fellow, and talmud Torah, which is equal to them all.